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<br />("ABA") and the Meteoric Water Mobility Procedure ("MWMP") were used to quantify the <br />potential chemical activity of the underdrain fill. The available information describing the <br />information generated by these tests at that time has been submitted to you by CC&V with <br />our letter of June 19, 1994. <br />Specifically, results from LA Abrasion and Slake Durability testing performed on weathered <br />surface samples and from ABA and MWMP testing performed on drill cuttings from six <br />borings were submitted to the OMLR in the form of a letter report prepared by Cripple <br />Creek & Victor Gold Mining Company on June 19, 1994. The OMLR responded that they <br />did not believe they could accept the LA Abrasion value of 47.7 percent loss reported in that <br />submission and indicated that 40 percent loss, based we believe on guidance from the coal <br />program, would be the maximum accepted value. In their response to CC&V's letter the <br />OMLR also stated that the concentration of some constituents analyzed during the MWMP <br />testing exceeded surface- or ground-water quality standards. <br />During subsequent discussions with OMLR, which included a field inspection, it was decided <br />that the LA Abrasion test method may not be appropriate to quantify the durability of the <br />underdrain fill materials. It was suggested that instead tensile strength may be a better <br />indicator of the behavior of the underdrain fill materials during loading and operation of the <br />leaching facility. Therefore, Golder Associates Inc. ("Golder") performed point load testing <br />on representative samples of the granodiorite collected from the potential borrow source <br />located on the northeastern portion of the pad, southeast of Arequa Gulch, the location <br />visited during the OMLR inspection. That location contains more competent granitic <br />material than the other areas that were sampled and the greater degree of competence appears <br />to be associated with a lesser amount of biotite than occurs in the granodiorite in areas that <br />have been opened to the northwest of Arequa Gulch. <br />Using testing procedures outlined in The Equivalent Core Diameter Method of Size and Shape <br />Correction in Point Goad Testing', twenty seven (27) specimens of this granodiorite from the <br />visited site were tested for tensile strength over the past week. The results of the testing are <br />included as Attachment 1. <br />Summarizing the data in Attachment 1, the mean tensile strength of the more competent <br />granodiorite specimens was 1,230 psi. The standard deviation, maximum, and minimum <br />tensile strengths of the granodiorite specimens were ±271, 1,800, and 800 psi respectively. <br />Since the mean value of tensile strength is in excess of four times greater than the minimum <br />required value of 300 psi established by OMLR, CC&V believes that this granodiorite source <br />located southeast of Arequa Gulch will be a suitable source of durable material to develop as <br />underdrain fill as well as bedding material for the pipe located beneath the underdrain rock. <br />CC&V requests your confirmation of the suitability and approval of use at your earliest <br />convenience. <br />During the site inspection noted above, which occurred on June 28, 1994, representatives of <br />OMLR, Golder, and CC&V noted that it may difficult to limit the maximum particle size of <br />2 <br />